A supercharged internal combustion engine may comprise at least two cylinders, where each cylinder has an outlet for discharging exhaust gases. The exhaust lines of the cylinders may be configured to form an exhaust manifold. The exhaust manifold may be connected to an inlet of a turbocharger to increase power density over a wider engine operating range.
One approach is to merge the exhaust lines of the cylinders to form a first group and second group such that the dynamic wave phenomena in the exhaust lines of the cylinders of a group have the least possible adverse effect on one another. Another approach is to merge the exhaust lines of the cylinders into a single overall exhaust line upstream of the turbine. Further, concepts may be known in which the two exhaust manifolds can be connected to and separated from one another.
A potential issue noted by the inventors with the above approaches is that when exhaust lines of cylinders may be merged into a first and second group the charge exchange may interfere detrimentally. This approach may not allow the turbine to be operated optimally at high loads. Another potential issue noted by the inventors is a single overall exhaust line provides a large volume of exhaust gas upstream of the turbine and may impair turbine operation at low exhaust gas flow rates. Further, connecting exhaust manifolds may lead to a residual gas problem and knocking being abetted.
One potential approach to at least partially address some of the above issues relates to a supercharged internal combustion engine having at least one cylinder head with at least two cylinders in which a cylinder has at least one outlet opening for discharging the exhaust gases. Further, an outlet opening may be adjoined by an exhaust line and the at least two cylinders may be configured in such a way as to form two groups with at least one cylinder wherein the exhaust lines of the cylinders of the cylinder group merge to form an overall exhaust line such that an exhaust manifold is formed. The two overall exhaust lines may be connected to a two channel turbine which comprises a rotor which is mounted on a rotatable shaft in a turbine housing such that one overall exhaust line is connected to one of the two inlet openings of the turbine. Wherein an inlet opening is adjoined by one channel of the turbine and the two channels may be separated from one another as far as the rotor by means of a housing wall such that the exhaust-streams of the two channels may be conducted separate from one another to the rotor. Further, the two channels of the turbine can be connected to one another within the turbine housing by virtue of at least one opening in the housing wall upstream of the rotor and downstream of the inlet openings being opening up. This may allow for optimal operation of the turbine at high exhaust gas flow rates and low exhaust gas flow rates.
Another potential approach is a method for an engine comprising adjusting a displaceable wall part which serves to open or close an opening in the housing wall of a turbine housing upstream of a rotor and downstream of inlet openings to fluidly connect two channels of the turbine housing via the opening responsive to exhaust gas flow rate over a threshold. In this way, it is possible to adjust the communication between multiple passages in the turbocharger housing depending on the operating conditions of the engine to improve overall performance.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that may be further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.